Intake manifold



June 5, 1962 D. BURCH 3,037,493

' INTAKE MANIFOLD Filed Feb. 5, 1960 tig sscouomv v INVENTOR.

Z7 BY 454/25 Q dwi ZWM ATTOHJVZY United States Patent 3,037,493 INTAKE MANIFOLD Lewis D. Burch, Birmingham, Mich., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Feb. 5, 1960, Ser. No. 6,951 3 Claims. (Cl. 12352) This invention relates to intake manifolds for internal combustion engines and more particularly to an intake manifold providing equal distribution of the air-fuel charge to each of the engine cylinders.

In internal combustion engines, an intake manifold is necessary to convey the air-fuel mixture from a carbureting device to the engine cylinders for combustion therein. The carburetor device may take the form of a carburetor having primary and secondary outlet passages leading directly to the intake manifold, the primary passages conveying the air-fuel mixture during periods of low engine speed and the secondary passages being arranged to supply air-fuel mixture, along with the primary passages, during periods of high engine speed. This may be accomplished by means of a carburetor having an even or an odd number of barrels or passages, that is, a fourbarrel or threeharrel carburetor device.

In most intake manifolds, the intake ports communicating with the carburetor device are arranged in such a manner that the primary intake ports are disposed at one side or the other of the main manifold portion so that the charge distributed by the intake manifold is unequal to some of the cylinders as compared to others. This leads to inefficient engine operation and poor fuel economy;

The device in which this invention is embodied comprises, generally, an intake manifold having a central plenum chamber extending lengthwise of the engine and having a plurality of ram pipes connected thereto for conveying the air-fuel charge to the engine cylinders. A carburetor mounting pad is located centrally of the plenum chamber and has intake ports formed therein and communicating with the carburetor. The intake ports are so arranged as to place the primary and secondary intake ports equidistant from all of the ram pipes.

With a construction of this nature, the charge distribution to the engine cylinders will be equal under all conditions of operation of the engine, making the engine more efficient in its operation and greatly increasing the fuel economy thereof.

These and other advantages will become more apparent from the following description and drawings in which:

FIGURE 1 is a plan view of a V-type engine, with parts broken away and in section, to illustrate the position and construction of the intake manifold embodying this invention.

FIGURE 2 is a plan view of a V-type engine, with parts broken away and in section, illustrating a modification of the intake manifold illustrated in FIGURE 1 and suitable for use with a three-barrel carburetor.

Referring more particularly to the drawings, 'a modification of the intake manifold is illustrated in FIGURE 1. A V-type internal combustion engine, illustrated generally by the numeral 10, is provided with two rows of cylinders 12 on opposite sides of the longitudinal centerline thereof. Cylinder heads 14 are secured to the engine block '16 in some suitable manner, and contain the valves and spark plugs which make the engine operative. Cover members 18 enclose the valve rocker arms and other operating mechanism to prevent dirt, water and other foreign materials from coming in contact therewith, the covers 18 being secured to the heads 14 in some suitable manner, as by bolts 20. Exhaust manifolds 22 are also provided to convey the exhaust gases through a suitable mufiier and exhaust pipe to the atmosphere.

The intake manifold, illustrated generally by the numeral 24, is shown to be disposed lengthwise of the engine 10 and generally centrally thereof. The manifold 24 has a central portion 26 and a plurality of groups of ram pipes 28, extending at generally right angles therefrom and toward the engine block 16 adjacent the end cylinders in each of the rows 12. The manifold is secured to the engine by flanges 30, located on the ends of the groups of ram pipes 28, which are bolted or otherwise secured, as by bolts 32.

The longitudinal walls 34, along with the top and bottom, of the manifold 24 provide a plenum chamber 36 which receives the air-fuel charge from the carbureting device located above the manifold. The plenum chamber 36 connects with passages 38 in the ram pipes which in turn lead to outlet ports 40, the outlet ports being aligned with similarly shaped ports in the engine 10 for conveying the charge to the cylinders.

At the junction between the plenum chamber 36 and the ram pipe passages 38, charge distribution Zones 42 are provided from which the charge is passed through the ram pipe passages 38 to the engine cylinders.

The upper surface of the central portion 26 is formed to provide a pad 44 to receive a carburetor device, which may be bolted or otherwise secured thereto, the threaded openings 46 being provided for this purpose. The carburetor pad 44 has a plurality of apertures, or ports, formed therethrough, primary apertures 48 communicating with the primary outlets of the carburetor device and secondary apertures 50 communicating with the secondary outlets of the carburetor device.

It is to be noted that primary apertures 48 are positioned centrally of the central portion 26, and centrally of the plenum chamber 36, in a lateral direction with respect to the engine 10. Further, the secondary inlet ports or apertures 50 are located on the longitudinal centerline of the central portion 26 and are spaced on opposite sides of the primary inlet ports 48. With such location of the primary and secondary inlet ports, it is seen that the charge distribution through the plenum chamber 36 and to the distribution zones 42 will be equal in both directions, Whether the primary inlets alone are receiving the charge from the carburetor or whether both the primary and the secondary inlet ports receive the charge. Since the charge is uniformly distributed to the zones 42, the passage of the charge through the passages 38 in the ram pipes '28 and through the outlet ports 40, will be equal, and the charge passing to each of the cylinders will be equal.

Referring to FIGURE 2, a modification of the intake manifold is shown on a similar V-type internal combustion engine 10 having rows of cylinders 12 and other parts similar to those illustrated in FIGURE 1 and bearing like reference numerals.

The intake manifold, illustrated generally by the numeral 60 in FIGURE 2, is shown to have a central portion 62 in which is defined a plenum chamber 64 and from which extends the groups of ram pipes 66. The ram pipes are secured to the engine 10 by the flanges 68, the flanges being held in place by bolts 70 or some other suitable attaching means. The ram pipes 66 have passages 71 formed therein to convey the air-fuel mixture to the outlet ports 72 and thus to the engine cylinders.

A carburetor mounting pad 74 is provided centrally of the central portion 62 to receive a carbureting device which may be secured to the pad 74 by bolts or the like, the threaded openings 76 being provided for this purpose. A plurality of openings or ports are formed through the central portion 62 of the manifold 60 corresponding to the primary and secondary outlets of the carburetor device. In this instance the central opening 78 corresponds to the primary outlets of the carburetor, and the outside apertures 80, spaced on opposite sides of the primary port 78, correspond to the secondary outlets of the carburetor device. All three of the openings 78 and 80 are aligned on the longitudinal centerline of the intake manifold 60 such that the air-fuel charge to the charge distribution zones 82' will be equal, whether the primary opening 78 is receiving all the charge from the carburetor, or whether the secondary openings 86* are receiving some of the air-fuel mixture as well. Since the passage of the mixture to the distribution zones 32 at opposite ends of the plenum chamber 74 is equal, the passage of the charge to the pipes 70 and the ram pipes, and to the cylinders through the outlets 72, will be equal during all conditions of operation of the engine.

Thus, an intake manifold is provided for a V-type internal combustion engine which permits an equal distribution of the air-fuel charge to each of the engine cylinders for proper operation of the engine.

What is claimed:

1. An intake manifold for an internal combustion engine having parallel rows of cylinders on opposite sdies of said engine, said manifold being formed to provide an elongated plenum chamber adapted to be disposed lengthwise between said rows of cylinders and groups of substantially identical ram pipes connected in side-by-side relation at opposite ends of said plenum chamber and extending toward the cylinders at the ends of said rows, said plenum chamber at the inlet ends of said ram pipes being formed to provide fluid distribution zones, and primary and secondary inlet means for said manifold and connected to said plenum chamber between said zones, said secondary inlet means being spaced on opposite sides of said primary inlet means lengthwise of said plenum chamber to provide equal distribution of fuel to said zones and to said ram pipes during all conditions of operation of said engine.

2. An intake manifold for an internal combustion engine having parallel rows of cylinders on opposite sides of said engine, said manifold being formed to provide an elongated plenum chamber adapted to be disposed lengthwise between said rows of cylinders and groups of rain pipes connected in side-by side relation at opposite ends of said plenum chamber and extending toward the cylinders at the ends of said rows, said plenum chamber at the inlet ends of said ram pipes being formed to provide fluid distribution zones, and inlet means in said manifold and connected to said plenum chamber and including a pair of primary ports and a pair of secondary ports, said primary ports being arranged laterally of said manifold and centrally of said plenum chamber, said secondary ports being aligned longitudinally of said manifold and on opposite sides of said primary ports, said primary and secondary ports providing equal and uniform distribution of fuel to said zones and to said ram pipes during all conditions of operation of said engine.

3. An intake manifold for an internal combustion engine having parallel rows of cylinders on opposite sides of said engine, said manifold being formed to provide an elongated plenum chamber adapted to be disposed lengthwise between said rows of cylinders and groups of ram pipes connected in side-by-side relation at opposite ends of said plenum chamber and extending toward the cylinders at the ends of said rows, said plenum chamber at the inlet ends of said ram pipes being formed to provide fluid distribution zones, and inlet means in said manifold and connected to said plenum chamber and including a primary port and a pair of secondary ports, said primary port being disposed midway between the ends of said plenum chamber, said secondary ports being aligned with said primary port longitudinally of said manifold and on opposite sides thereof, said primary and secondary ports providing equal and uniform distribution of fuel to said zones and to said ram pipes during all conditions of operation of said engine.

References Cited in the file of this patent UNITED STATES PATENTS 2,098,424 Kolimbat Nov. 9, 1937 2,733,695 Goodridge Feb. 7, 1956 2,845,911 Gill Aug. 5, 1958 2,886,021 Burrell May 12, 1959 2,927,564 Turlay et al. Mar. 8, 1960 

